Tree Bumble Bee

This won't go down as my best photo but I was pleased to find this Bumble Bee.  The  Tree Bumble Bee, Bombus hypnorum, is a relatively new species to the UK. They first appeared in Hampshire in 2001 and have steadily spread out and are now found as far north as the southern of Scotland. 

Unlike other species, Tree Bumble Bees like to nest above ground. Although their normal choice would be in a tree, they've taken a liking to bird boxes and, to gain occupancy, the queens are happy to challenge and oust a resident Blue Tit.  Another strange place in which they like to nest is in tumble drier vents! 
Their colonies can reach 400 bees, which is double the size of other species of Bumble Bees.  They are some of the earliest to appear, flying between March and July , although they can have a second nesting later in the year if the weather permits. 

Bumble Bees, generally. don't sting unless really provoked.  The Tree Bumble Bees are a bit more aggressive but only if you try go to near the nest where the drones fly around the entrance, to protect it and in wait of a new queen to emerge.